Encyclopedia Mythica -
A thorough hyperlinked article.
Leto, Greek Mythology
A very thorough site from Carlos Parada. Genealogical information, an image, text references, background, and more. A good place to start your research.
A site with good general information.
Mythology Zeus Lovers
Includes information on all of Zeus' lovers, including Leto.
Another thorough article with general information. Lots of imbedded hyperlinks.
Genealogies and Family Trees
From Encyclopedia Mythica
Greek Mythology Gods
Adapted from Edith Hamilton. This page is a hyperlinked genealogy of the major gods.
Family Tree of Greek Gods and Goddesses
From the University of Michigan, a nice hyperlinked family tree of both Greek and Roman gods. If you are interested they also have trees for Norse gods.
The McGraw-Hill Companies, Inc..